Abrading machine



Dec; 18, 1956 A. N. EMMONS 2,774,199

ABRADING MACHINE Filed Sept. 15, 1951 4 Sheets-Sheet l I #NE ENTOR.

Dec. 18, 1956 A. N. EMMONS 2,774,199

ABRADING MACHINE Filed Sept 15, 1951 4 Sheets-Sheet 2 H r V 2 g VIgZENTOR.

Dec. 18, 1956 A N. EMMONS ABRADING MACHINE 4 Shee'ts-Sheet 3 Filed Sept. 15, 1951 Z a ENTOR. fiwi fimaw -m EI Dec. 18, 1956 A. N. EMMONS ABRADING MACHINE 4 Sheets-Sheet 4 Filed Sept. 15., 1951 a gVENTOR.

United States Patent ABRADING MACHINE Arthur N. Emmons, Nedrow, N. Y., assignor to The Porter-Cable Machine Company, Syracuse, N. Y., a corporation of New York Application September 15, 1951, Serial No. 246,785

3 Claims. (Cl. 51-177) This invention relates to portable abrading machines and has to do more particularly with a machine of that type wherein the abrading element consists of a pad having an abrading face or surface, the pad being operated to efiect a rubbing action on the work by an orbital or reciprocating motion.

The invention has an object a machine of the type referred to embodying a particularly simple construction economical to manufacture, and the machine embodying a self contained eflicient dust collecting mechanism.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a side elevational view of a machine embodying my invention with the lower portion of the machine shown in vertical sectional view.

Figure 2 is a vertical sectional view taken on line 2-2, Figure 1, with the upper or motor portion of the machine shown in elevation.

Figure 3 is a view taken on line 3-3, Figure 1.

Figure 4 is a view taken on line 44, Figure l.

The abrading machine consists of a base member 111 including a gear compartment and a fan compartment. As here shown, the base consists of an integral casting, the upper portion 11 of which is of substantially cylindrical formation and comprises a fan housing having a discharge passage 12 and a centrally arranged inlet passage 13.

The lower portion of the base is formed with a gear compartment 14, the top of this compartment being defined by a partition wall 15 in which the inlet passage 13 is formed. More specifically, this compartment contains a pair of spaced apart circular shaped bosses or housings 16 which are provided with circular openings at the lower edge of the base, the openings being closed by cap members 17 detachably secured to the base as by screws 18 threading into apertures 19 formed in the bottom side of the base. There is a smaller substantially circular shaped boss or housing 21 positioned between the bos'ses 16 and which has a bottom wall 22 and is formed with an opening at its upper end.

A pair of crank shafts 23, 24, are journalled in the gear compartment. The upper ends of the shafts 23, 24, are journalled in bearings 25 mounted in the top wall of the bosses 16, and these shafts are journalled intermediate their ends in bearings 27 positioned in the closure caps 17, see Figure 1.

The crank shaft 23 has a depending portion 29, and the shaft 24 a similar portion 30. The portions 29, 30, have detachably secured thereto, as by screws 31, cap portions 23. The portions 29, 30 and their cap portions 32 are apertured to receive bearings 33 and in which are mounted stems 34 fixed to the pad 35 and extending upwardly therefrom, the stems being retained "ice in the bearings 33 as by snap rings 36. The portions 29, 30-32 are recessed eccentrically with the axes of the shafts 23, 24, whereby the portions 29, 3032 form crank members to effect orbital or reciprocating motion of the pad 35 upon rotation of the shafts 23, 24.

The crank shafts are rotated in unison by a motor 40 aflixed to the upper end of the fan housing 11 and having its armature shaft 41 extending through the aperture 13 and being journalled in a bearing 42 mounted in the upper portion of the gear compartment center boss 21. A pinion gear 45 is alfixed to the lower end of the motor shaft 41 and is arranged in mesh with a gear 46 afiixed to the crank shaft 23 ad a gear 47 afiixed to the crank shaft 24. The portions 29, 30, act as a counterbalance to reduce vibration from the reciprocation of the pad 35, and additional counterbalancing weights 48 are affixed to the shafts 23, 24, adjacent their upper ends.

A suction fan 50 is mounted in the fan compartment 11 on the motor shaft 41 and functions to create an upward suction through the aperture 13 and discharge through the discharge passage 12.

Sheet abrading material, such as sandpaper 51, is positioned on the face of the pad 35, with the ends of the sheet detachably clamped to the upper surface at the ends of the pad by clamping members 52. This arrangement for detachably securing the abrading sheet, to the pad is disclosed in Patent No. 2,519,620, issued August 22, 1950. The pad 35 is encircled by a hood 54 of general rectangular formation depending from the lower side of the base to which it is attached as by screws 55. The hood 54 is of suflicient dimension to permit the orbital movement of the pad.

Referring to Figures 2 and 3, the partition wall 15 is of substantially greater width than the bosses 16 in the gear compartment, whereby there is a space 66 extending along each side of the base between the bosses 16 and side walls 61 of the base. This space provides a passage on each side of the gear compartment leading into the inlet aperture 13 of the fan housing. With this arrangement, the dust created by the action of the pad is drawn upwardly over the pad through the passages and into the inlet aperture 13, as indicated by arrows 62. However, the motion transmitting mechanism between the motor and the pad is totally enclosed in the gear housings. The dust drawn into the fan chamber is discharged by the fan 50 through the discharge outlet 12 to which there is detachably connected, as by screws 64, a nozzle member 65. A suitable dust collecting bag 66 is attached to the nozzle member 65.

The base is formed on opposite sides with bosses 67 to which the ends 68 of a handle yoke 69 are attached by means of screws 70.

What I claim is:

1. A portable power operated abrading machine comprising a base of substantially rectangular shape provided on its upper surface with a centrally arranged fan compartment and with a gear compartment in its lower portion, said gear compartment consisting of a pair of spaced apart housings and a central housing positioned intermediate said spaced apart housings and communicating therewith, a crank shaft journalled in each of said spaced apart housings and said shafts having crank portions depending from the gear compartment, an abrasive pad operatively connected to said crank portions for movement thereby, a motor mounted above the fan compartment and having its shaft extending through the fan compartment into the central housing of the gear compartment, a suction fan mounted on the motor shaft in the fan compartment, gearing arranged in said housings and operatively connecting said motor shaft to said crank shafts, said central housing being smaller in dimension than said spaced apart housings, and said base being termes iwith anertutes. 2 .1 appo ite ides. at said en ral.

housing and forming an inlet passage to said fan compartment.

7-. An a adin imaq i e as' efi ed in. claim, 1; wh r in t an omp n and e ear housing are formed integral with the base;

' 3. A portable power operated 'abrading machine comprising an integral base member having a top wall and being formed with a centrally arranged, substantially s r nqr ca i tan m ar ment ex ending" pwardly' the top wall, a pair ofspaced apart gear housings extending downwardly from the topwall of the base, memher, a central gear housing arranged intermediate said spaced apart honsings and communicating therewith, a

shaft journalled in each ofsaid spaced apart housings.

depending downwardly therefrom, a crank member mounted on the depending end ofeach of said shafts, a

rectangular abrading' pad'conneeted to said crank mem- T bers, a motor mountedon the upper end of the fan compartment'andhaving. its shaft? extending downwardly 20 through the fan compartment into said central gear housing, gearing arranged in said housings and operatively connecting said motor shaftto saidrcrank shafts, said central housing being smaller in dimension than said spaced apart housings, and the top ,wall of the base member having apertures jat opposite sides of said central housing and forming an inlet passage to said fancompartment. H j 7 References Cited in the filedf this patent UNITEDSTATES PATENTS 1,868,507

652,046 France Oct. 26,192 

